J/A+A/618/A4ivo://CDS.VizieR/J/A+A/618/A4doi:10.26093/cds/vizier.36180004CDSCernicharo J.Guelin M.Agundez M.Pardo J.R.Massalkhi S.,Fonfria J.P.Velilla Prieto L.Quintana-Lacaci G.Marcelino N.,Marka C.Navarro S.Kramer C.2018-11-05T10:52:51Z2018-10-03T08:08:44ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.fratomic-physicsastronomical-modelscarbon-starsspectroscopyThis work presents a detailed analysis of the laboratory and astrophysical spectral data available for ^28^SiC_2_, ^29^SiC_2_, ^30^SiC_2_, Si^13^CC, and Si_2_C. New data on the rotational lines of these species between 70 and 350GHz have been obtained with high spectral resolution (195kHz) with the IRAM 30m telescope in the direction of the circumstellar envelope IRC+10216. Frequency measurements can reach an accuracy of 50kHz for features observed with a good signal to noise ratio. From the observed astrophysical lines and the available laboratory data new rotational and centrifugal distortion constants have been derived for all the isotopologues of SiC_2_, allowing to predict their spectrum with high accuracy in the millimeter and submillimeter domains. Improved rotational and centrifugal distortion constants have also been obtained for disilicon carbide, Si_2_C. This work shows that observations of IRC+10216 taken with the IRAM 30m telescope, with a spectral resolution of 195kHz, can be used for any molecular species detected in this source to derive, or improve, its rotational constants. Hence, IRC+10216 in addition to be one the richest sources in molecular species in the sky, can also be used as a state-of-the-art spectroscopy laboratory in the millimeter and submillimeter domains.2018A&A...618A...4Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/618/A4CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/330/676 : IRC+10216 Silicon and sulfur chemistry (Willacy+ 1998)J/ApJ/688/L83 : Detection of C_5_N^-^ in IRC +10216 (Cernicharo+, 2008)J/ApJS/177/275 : 1.3 and 2mm survey of IRC+10216 (He+, 2008)J/ApJS/190/348 : 1mm spectral survey of IRC+10216 + VY CMa (Tenenbaum+, 2010)J/ApJS/193/17 : Spectral-line survey of IRC+10216 at 293-355GHz (Patel+, 2011)J/A+A/545/A12 : Chemistry of IRC+10216 inner wind modelled (Cherchneff, 2012)J/A+A/574/A56 : IRC +10216 17.8GHz-26.3GHz spectrum (Gong+, 2015)J/ApJ/806/L3 : CW Leo disilicon carbide (SiCSi) discovery (Cernicharo+, 2015)J/A+A/601/A4 : IRC+10216 carbon chains mapped with ALMA (Agundez+, 2017)J/A+A/606/A74 : IRC +10216 13.3GHz-18.5GHz spectrum (Zhang+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/618/A4https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/618/A4http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/618/A4https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/618/A4https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/618/A4http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/618/A4GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/618/A4/tablea2Measured frequencies for the rotational lines of SiC_2_recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ1Quantum number J (upper level)instr.det.qeintKa1Quantum number Ka (upper level)phys.atmol.qnintKc1Quantum number Kc (upper level)phys.atmol.qnintJ0Quantum number J (lower level)instr.det.qeintKa0Quantum number Ka (lower level)phys.atmol.qnintKc0Quantum number Kc (lower level)phys.atmol.qnintFobsObserved frequency of the lineMHzem.freq;spect.linedoublee_FobsUncertainty (1 sigma) of the observed frequencyMHzstat.errorfloatFcalcCalculated frequency of the lineMHzem.freq;spect.line;meta.modelleddoubleDeltaFDifference between observed and calculated frequenciesMHzstat.fit.residualfloatRefReference (1)meta.ref;pos.framecharComFit comments (2)stat.fit.param;meta.modelledcharJ/A+A/618/A4/tablea5Measured rotational lines of ^29^SiC_2_recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ1Quantum number J (upper level)instr.det.qeintKa1Quantum number Ka (upper level)phys.atmol.qnintKc1Quantum number Kc (upper level)phys.atmol.qnintJ0Quantum number J (lower level)instr.det.qeintKa0Quantum number Ka (lower level)phys.atmol.qnintKc0Quantum number Kc (lower level)phys.atmol.qnintFobsObserved frequency of the lineMHzem.freq;spect.linedoublee_FobsUncertainty (1 sigma) of the observed frequencyMHzstat.errorfloatFcalcCalculated frequency of the lineMHzem.freq;spect.line;meta.modelleddoubleDeltaFDifference between observed and calculated frequenciesMHzstat.fit.residualfloatRefReference (1)meta.ref;pos.framecharComFit comments (2)stat.fit.param;meta.modelledcharJ/A+A/618/A4/tablea8Measured rotational lines of ^30^SiC_2_J0Quantum number J (lower level)instr.det.qeintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ1Quantum number J (upper level)instr.det.qeintKa1Quantum number Ka (upper level)phys.atmol.qnintKc1Quantum number Kc (upper level)phys.atmol.qnintKa0Quantum number Ka (lower level)phys.atmol.qnintKc0Quantum number Kc (lower level)phys.atmol.qnintFobsObserved frequency of the lineMHzem.freq;spect.linedoublee_FobsUncertainty (1 sigma) of the observed frequencyMHzstat.errorfloatFcalcCalculated frequency of the lineMHzem.freq;spect.line;meta.modelleddoubleDeltaFDifference between observed and calculated frequenciesMHzstat.fit.residualfloatRefReference (1)meta.ref;pos.framecharComFit comments (2)stat.fit.param;meta.modelledcharJ/A+A/618/A4/tablea11Measured rotational lines of Si^13^CCComFit comments (2)stat.fit.param;meta.modelledcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ1Quantum number J (upper level)instr.det.qeintKa1Quantum number Ka (upper level)phys.atmol.qnintKc1Quantum number Kc (upper level)phys.atmol.qnintJ0Quantum number J (lower level)instr.det.qeintKa0Quantum number Ka (lower level)phys.atmol.qnintKc0Quantum number Kc (lower level)phys.atmol.qnintFobsObserved frequency of the lineMHzem.freq;spect.linedoublee_FobsUncertainty (1 sigma) of the observed frequencyMHzstat.errorfloatFcalcCalculated frequency of the lineMHzem.freq;spect.line;meta.modelleddoubleDeltaFDifference between observed and calculated frequenciesMHzstat.fit.residualfloatRefReference (1)meta.ref;pos.framecharJ/A+A/618/A4/tablea14Measured rotational lines of Si_2_CRefReference (1)meta.ref;pos.framecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ1Quantum number J (upper level)instr.det.qeintKa1Quantum number Ka (upper level)phys.atmol.qnintKc1Quantum number Kc (upper level)phys.atmol.qnintJ0Quantum number J (lower level)instr.det.qeintKa0Quantum number Ka (lower level)phys.atmol.qnintKc0Quantum number Kc (lower level)phys.atmol.qnintFobsObserved frequency of the lineMHzem.freq;spect.linedoublee_FobsUncertainty (1 sigma) of the observed frequencyMHzstat.errorfloatFcalcCalculated frequency of the lineMHzem.freq;spect.line;meta.modelleddoubleDeltaFDifference between observed and calculated frequenciesMHzstat.fit.residualfloatComFit comments (2)stat.fit.param;meta.modelledchar